Is the periodic table (elemental chart) “complete” at present?

In one sense, the periodic table is complete up to a point: all chemical element slots through atomic number 118 have been discovered or synthesized. In 2016 the last missing entries of the seventh period – elements 113, 115, 117, and 118 – were officially confirmed and named (nihonium, moscovium, tennessine, and oganesson), thus filling out the table’s seventh row (cen.acs.org). However, the notion that the elemental chart is permanently complete could not be further from the truth (www.americanscientist.org). The periodic table remains open-ended, with new elements beyond 118 potentially waiting to be created and added as science progresses. In short, while the known chart is full through element 118, it is not considered a finished entity in a long-term sense.

After element 118, a new period would begin – and it remains blank. No element with atomic number 119 or higher has yet been synthesized or confirmed, so officially the table stops at 118 for now. These super-heavy elements (119, 120, and beyond) are hypothesized to exist, and scientists are actively searching for them. In fact, the global race to discover element 119 (and 120) is well underway (cendevredesign.acs.org). The first team to create element 119 would essentially start an eighth row of the periodic table (cendevredesign.acs.org), marking the first addition to the chart since 2016. Laboratories in several countries – notably Japan, the United States, Germany, Russia, and China – have been developing powerful experimental setups to attempt these syntheses (cendevredesign.acs.org) (cendevredesign.acs.org). Among them, Japan’s RIKEN institute has emerged as a frontrunner: it invested in a custom-built particle accelerator upgrade specifically to hunt for element 119 one atom at a time (cendevredesign.acs.org). Meanwhile, U.S. researchers at Lawrence Berkeley National Laboratory (LBNL) have been pursuing element 120 with their own approach (cendevredesign.acs.org). These concerted efforts show that the table is poised to grow, even though the next elements remain undiscovered so far.

Pushing beyond element 118 is an enormous scientific challenge. All known superheavy elements are extremely unstable, often decaying in a split-second or less (www.scientificamerican.com). The greater the atomic number, the more protons jam-packed into a nucleus – and generally, the more quickly that nucleus falls apart. This means any new element must be created and detected almost instantaneously before it vanishes. Researchers synthesize superheavy atoms by smashing lighter nuclei together at very high speeds, hoping the fragments fuse into a new, heavier nucleus. The probabilities are extremely low: for example, when RIKEN’s team in Japan discovered element 113 (nihonium), they had to perform about four trillion atomic collisions to produce three atoms of nihonium, each of which existed for only a few milliseconds (cendevredesign.acs.org). That was enough to confirm its discovery, but it vividly demonstrates the difficulty of making and observing such fleeting atomic species. Attempting to reach element 119 or 120 is even harder – it requires heavier projectile ions, rarer target materials, and months or years of sustained experiment, all for a handful of decay signals. So far, no experiment has definitively seen element 119, underscoring how demanding this frontier is.

Despite the hurdles, recent advancements give reason for optimism. Cutting-edge facilities and techniques are improving the odds of success. In 2020, RIKEN completed a major upgrade to its heavy-ion accelerator and separator systems, boosting the beam intensity and energy needed to form element 119 (link.springer.com) (link.springer.com). Similarly, scientists in the U.S. have developed a novel method to produce superheavy nuclei more efficiently. In mid-2024, a team at LBNL reported using an intense beam of titanium-50 (a rare isotope) to successfully forge atoms of element 116 (livermorium) in a new way (www.scientificamerican.com). Livermorium had been made before, but this experiment was groundbreaking because it proved a more effective fusion approach that could be applied to reach heavier, yet-unknown elements (www.scientificamerican.com). According to researchers, this technique “paves the way for the synthesis of new, even heavier elements” by overcoming some prior limitations (www.scientificamerican.com). Each incremental innovation – whether stronger accelerators, improved detectors, or creative reaction choices – increases the likelihood that elements 119, 120, and beyond will eventually be created in the laboratory.

What lies beyond the current table? The truth is, nobody knows exactly how far the periodic table can ultimately extend. Theoretical models predict that nuclei might become a bit more stable again in an “island of stability” around certain high atomic numbers (possibly in the 120s), which raises hope that superheavy elements in that region could live long enough to study (www.scientificamerican.com). Even if those longer-lived superheavy atoms exist, reaching them will require pushing technology to its limits. At some point, fundamental physical constraints – such as the immense electrostatic repulsion in ultra-heavy nuclei or relativistic effects on electrons – may impose a practical upper limit on the periodic table. Scientists have speculated about a possible end to the table (some estimates range from around element 126 to somewhere around 150 or beyond), but no one can say for sure where the cutoff lies. What we can say is that as of today the elemental chart is not a closed book. It continues to grow gradually: each time a new element is synthesized and confirmed, another slot gets filled and our understanding of atomic science expands. In summary, the periodic table is complete only up to the elements we have discovered so far – it remains incomplete in a broader sense, with ongoing research poised to add new entries as soon as nature allows (cendevredesign.acs.org).

Further Reading:

Felicity Nelson (2025). “How Japan took the lead in the race to discover element 119.” Chemical & Engineering News, 103(2), Jan 24, 2025. – Detailed report on the international efforts and challenges in synthesizing elements 119 and 120.
Jyllian Kemsley (2016). “Names for elements 113, 115, 117, and 118 finalized by IUPAC.” Chemical & Engineering News, Nov 30, 2016. – Announcement of the official naming of nihonium, moscovium, tennessine, and oganesson, completing the periodic table’s seventh row.
Max Springer (2024). “New Superheavy Element Synthesis Points to Long-Sought ‘Island of Stability’.” Scientific American, July 24, 2024. – News article on a breakthrough method for creating superheavy elements (using a titanium-50 beam) and its implications for reaching new elements beyond 118.
Eric Scerri (2019). “The Periodic Table at 150.” American Scientist, Oct 14, 2019. – Perspective on the past and future of the periodic table, arguing that the table is not a finished catalog but an evolving scientific tool.

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Is the periodic table (elemental chart) “complete” at present?

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